TechNotes Tips - Fertilization Archive

Potassium fertilization in the autumn will enhance the winter tolerance of bermudagrass. Potassium use on northern turfgrasses for enhancing winter injury tolerance is not as well documented.

Mid- to late- November is an excellent time for late-season fertilization of cool season turfgrasses. At this time, turfgrass plants have slowed or stopped topgrowth but root growth and photosynthesis continues. Nitrogen is the most critical element in late season fertilization of northern turfs. Nitrogen will extend the greening time later into the fall, promote root growth, contribute to carbohydrate accumulation, and promote early spring greenup. The rate of nitrogen applied during the fall depends on the source (quick-release or slow-release) but the normal recommended rate is between 1 and 1.5 pounds actual nitrogen per 1000 square feet.

Late season fertilization with nitrogen is a desirable practice on cool season turfgrasses. Nitrogen applied in mid to late fall can promote root growth, extended greening of the turf, early spring greenup and accumulation of carbohydrates. Late season fertilization treatments should be applied at the time shoot growth ceases (no longer removing clippings) but the turf is still green.

Late season fertilization with nitrogen on bermudagrass is a desirable practice in the southern United States. As you move north and closer to the transition zone, nitrogen fertilization of bermudagrass may enhance winter injury. Potassium fertilization in the autumn is a recommended practice to enhance the winter tolerance of bermudagrass.

Late season fertilization of warm season turfgrasses is an extremely important practice. Nitrogen promotes greening into the fall. However, as you move farther north and closer to the transition zone, nitrogen may enhance the risk of winter injury.

On warm season turfgrasses, especially bermudagrass, potassium applications need to be started around the beginning of October. In various studies, potassium has been associated with increased winter hardiness.

Late season fertilization of cool season turfgrasses in the northern U.S. is often made in November. Recommended rate for late season nitrogen application is 1.0 to 1.5 pounds nitrogen per 1000 square feet.

With the arrival of fall, nitrogen fertilization on cool season turfgrasses should be encouraged. Lawns that are spotty from the extremely dry summer should be fertilized to promote recovery.